Background Studies involving the association of blood albumin with prognosis in patients with chronic kidney disease (CKD) during intensive care unit (ICU) were scarce. Aim We investigated whether reduced blood albumin level independently associated with an increased risk of cardiovascular (CV) complications and 1-year mortality risk in ICU patients with CKD. Methods The Medical Information Mart for Intensive Care III (MIMIC-III) database was used. Disease diagnosis and death information among a number of 925 ICU patients with CKD, who have been measured for blood biochemistry, were recorded. Here, multivariable logistic regression Models were structured to evaluate the associations between blood albumin levels (first value on admission, maximum and minimum value during ICU) and risks for CV complications and 1-year mortality among these CKD patients. Results In 925 CKD patients, the number of CV complication with heart failure (HF), myocardial infarction (MI) or stroke was 470 (50.8%). 406 (43.9%) patients were dead during the follow-up of 1 year after patients were discharged. Our smooth curve results suggested a curvilinear relation on association between blood albumin level and risk of CV complications. The “inflection point” of blood albumin level that patients were at highest risk of CV complications was 3.4 g/dL. The almost linear relationship with a downward trend was observed on the association between blood albumin level and 1-year mortality risk. We found that reduced blood albumin level contributed to lower risk for CV complications and higher risk for 1-year mortality respectively when blood albumin levels in CKD patients were below 3.4 g/dL. Additionally, albumin therapy had an obvious modifying effect on the independent association, suggesting a possible improved effect of albumin therapy on risk of CV complications and 1-year mortality risk in these CKD patients. Conclusions Our study reported that reduced blood albumin levels in CKD patients during ICU were related to lower risk for CV complications and increased risk of 1-year mortality.